Liquid fuel nozzle



Paienced Sept. ii, 195?.

LIQUID FUEL NOZZLE Calvin MacCracken,

signor to Jet-Beet, Inc., corporation of New York New Rochelle, N. Y.,9.5--

Englewood, N. J., a

Application May 17, 1949, Serial No. 93,661

1 Claim.

This invention relates to improvements in liquid-fuel nozzles of thereturn-flow type.

The general object of the invention is to provide a liquid-fuel nozzleof the return-flow type which is simple in construction, efilcient andre liable in operation, easily cleaned, and capable of supplyingstrained liquid-fuel at low and accurately controllable rates. Thenozzle hereinafter described is especially intended for supplying liquidfuel at rates ranging from only about onequarter (#1) gallon to aboutone and three quarters (1%) gallons per hour, for combustion inhouse-heating, water-heating and other kinds of apparatus requiring onlya small amount of liquid-fuel. The liquid-fuel may be supplied to thenozzle at the customary pressure of about 100 pounds per square inch,and the return-flow may be controlled by any suitable valve, forexample, by the pressure regulating device described in my copendingapplication Ser. No. 70,773, filed January 13, 1949. Thus the quantityof liquid-fuel per hour which is emitted by the nozzle may be regulated.

The invention will be understood from the following description, takenin connection with the accompanying drawings in which a preferredembodiment of the invention is illustrated. Fig. 1 is a perspective viewof the liquid-fuel nozzle; Fig. 2 is an inverted sectional elevation, onan enlarged scale, on the planes 2-2 of Fig. 1; Fig. 3 is a perspectiveview of the perforated bushing; Fig. 4 is a perspective view of thecylindrical screen which (when used) cooperates with the outside of saidbushing; Fig. 5 is a perspective view of the liquid-fuel distributorlooking at the end which is provided with tangential grooves and with areturn passage; and Fig. 6 is a perspective view of the orifice nibwhich cooperates with the grooved end of the fuel distributor.

From Figs. 1 and 2 it will be apparent that the liquid-fuel nozzle has abase member 8 having a cavity Ill provided with an inlet passage l2, anda return passage l4 which communicates at IS with the center of thebottom of the cavity Ill. The mouth of the cavity I0 is shown internallythreaded as indicated at l6, so as to receive the externally threadedend of the nozzle tip to within which are assembled certain parts aboutto be described; but the nozble tip I8 may be secured to the base member8 v in any other suitable way. This assemblage of parts within the tipi8 includes a hollow bushing or strainer body 20, shown in Fig. 3, whichis provided with holes 22 and 24 located in the bottoms of grooves 28and 28. The bushing has an outside diameter considerably less than thediameter of the cavity to, so that said bushing is spaced-apart relativeto saidcavity as will be apparent from Fig. 2. At one end, the bushing23 is externally threaded, as shown at 30 in Fig. 3, so as to receivethe internally threaded endof the nozzle tip it; and at its other endthe bushing 20 is provided with a head 32 (shown as hexagonal) which isprovided with a centrally located hole 34 adapted to receive the returntube 36 which will be later described. A fine-mesh screen 38, shown inperspective in Fig. 4, having a diameter such that it cooperates withthe outside of the perforated portion of the bushing 20, may be includedin the assemblage of parts, as shown in Fig. 2. The return tube 36,shown in longitudinal cross-section in Fig. 2, is adapted to passthrough the bushing 20 and is provided with a cylindrical end 36' whichslidingly and closely fits into the central portion I5 of the returnpassage H in the base member 8, as is shown in Fig. 2. It will also beapparent from Fig. 2 that the return tube 36 is provided with anexternal flange 40 which cooperates with an internal flange 42 in thebushing-20. It will be noted that the cooperating faces of the flanges40 and 42 are inclined to the axis of the return tube 36, so that thesefacestightly abut, thusclosing at one end the annular space 31 betweenthe tube 36 and the bushing 20. Cooperating with the end of said returntube 3'5 is a fuel distributor 44, the form of which will be evidentfrom Figs. 2 and 5. It will be noted from Fig. 5, that one end of thefuel distributor 44 has a frusto-conical surface 45 and is provided withtangential slots 46 located therein as shown. The other end of the fueldistributor 44 is provided with a cylindrical cavity 41 adapted toreceive the end of the return tube 36; and the fuel distributor 44 isalso provided with an axial passage 48 communicating with a larger axialhole 50 which communicates with the cavity 41 and with the passagethrough the return tube 36 when that tube and the fuel distributor 44are assembled. It will be noted that the end of the tube 36 and thebottom of the cavity 41 in the fuel distributor 44 are provided withcooperating inclined surfaces, thereby insuring a tight connectionbetween the tube 36 and the fuel distributor 44, this being facilitatedby a slight clearance between the tube 36 and the distributor 44, asshown in Fig. 2. The orifice, nib 52, shown in perspective in Fig. 6 andin section in Fig. 2, is provided with a conical cavity 54 adapted tocooperate with the conical surface 45 on the end of the fuel distributor44; and said nib 52 is provided at its center with an orifice 56 whichis considerably smaller than the axial hole 48 in the fuel distributor44. As will be apparent from Fig. 2, the fuel distributor l4 and the nib52 define between them a conical whirling-space 58, hereinafter referredto. It will also be apparent from Fig. 2 that the nib 52 is nestedwithin the end of the nozzle tip l8 which is provided at its end with anaxial opening 60.

It will be evident from Fig. 2 that the perforated bushing 28 carrying(if desired) the screen 38, the return tube 88, the fuel distributor 44and the orifice nib 52 are easily assembled; and that they are held intight assembled relationship by the engagement of the external threads30 on the end of the bushing 20 with the internal threads in the nozzletip 18. When these parts have been so assembled, the external flange 48on the tube 38 cooperates with the internal flange 42 in the bushing 20;one end of the return tube 36 cooperates with the bottom of the cavity41 in the distributing member 44; and the orifice nib 52 cooperates withthe end of the fuel distributor 44 as has been described. Thisassemblage of parts may then be inserted in the cavity III in basemember 8, with the end of the tube 38 in the return passage I5, and maybe secured in the base member 8 by the engagement of the internallythreaded portion I6 of the base member 8 with the externally threadedportion of the nozzle tip I, as will be obvious from Fig. 2.

when the fuel nozzle is in use, the liquid-fuel entering through theinlet passage l2 flows into the cavity l0, through the screen 38 (if itis used), and through the holes 22 and 28 in the bushing 20 into theannular space 81 between the bushing 20 and the return tube 38, asindicated by the arrows in Fig. 2. From this annular space 31 theliquid-fuel flows into the annular space 88 between the fuel distributor48 and the nozzle tip II, and through the slots 46 into thewhirlingspace 58. From the whirling-space 58, some of the whirlingliquid-fuel fiows through the axial passages 48 and 58 and into thereturn tube 88 through which the fuel flows to the return passage ll;and the remainder of the liquid-fuel escapes from the central hole 56 inthe orifice nib 52 in the form of a spray for combustion purposes. Tofacilitate insertion of the tube 38 in the passage IS a slight clearancebetween these parts is provided; but this clearance should be as smallas practicable to minimize the passage of liquid fuel through thisclearance.

ished; and the other parts of the fuel nozzle may be made of brass. Inthe liquid-fuel nozzle illustrated and described, the return tube 38 andfuel distributor are separate and separable cooperating parts which isconsidered desirable. It

will be understood, however, that these parts may be made integral orpermanently connected. It

will also be understood that the orifice nib 82 and nozzle tip l8,instead of being separate and separable, may be integral or permanentlycongigclgedd Silt? modifications in construction may a e w ou departinfrom t What is claimed is: g he invention A liquid fuel nozzle of thereturn-flow type comprising a base member having a cavity provided withan inlet passage and in the center of its bottom with a return passage,the mouth of said cavity being internally threaded, and an assemblage ofparts adapted to cooperate with said base member and comprising a hollowperforated bushing receivable within said cavity in spacedapart relationthereto and having an externally threaded end, a return tube whichpasses through said bushing and is provided with a cylindrical end whichslidingly and closely fits into said return passage in the center ofsaid base member. said bushing and tube being provided with cooperatingflanges which substantially close the annular space between said bushingand tube near one end, a fuel distributo'r having a cavity cooperatingwith the end of said return tube and provided with an axial passagecommunicating with said tube, the end face of said fuel distributorbeing provided with tangential grooves, a nib having an axial orificeand cooperating with the grooved end of said fuel distributor and anozzle tip having an axial aperture and cooperating with said nib andprovided with an internally threaded opening cooperating with theexternally threaded end of said bushing and provided with an externallythreaded portion cooperating with the internally threaded mouth of saidbase member, whereby said perforated bushing, return pipe and fueldistributor, nib and nozzle tip may be secured together in assembledrelationship and then may be secured in said base member with the end ofsaid return tube closely fitting into the return passage in the centerof said base member.

CALVIN D. MACCRACKEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,644,372 Gray Oct. 4, 19272,079,430 Bargeboer May 4, 1937 2,120,388 Bargeboer June 14, 19382,439,257 Lum Apr. 6, 1948

